diff --git a/src/cli/gateway-cli/run.ts b/src/cli/gateway-cli/run.ts
index 6c0d2277f45..634a5b40a67 100644
--- a/src/cli/gateway-cli/run.ts
+++ b/src/cli/gateway-cli/run.ts
@@ -4,7 +4,7 @@ import path from "node:path";
 import type { GatewayAuthMode } from "../../config/config.js";
 import type { GatewayWsLogStyle } from "../../gateway/ws-logging.js";
 import {
-  CONFIG_PATH,
+  getConfigPath,
   loadConfig,
   readConfigFileSnapshot,
   resolveStateDir,
@@ -161,7 +161,7 @@ async function runGatewayCommand(opts: GatewayRunOpts) {
   const tokenRaw = toOptionString(opts.token);
 
   const snapshot = await readConfigFileSnapshot().catch(() => null);
-  const configExists = snapshot?.exists ?? fs.existsSync(CONFIG_PATH);
+  const configExists = snapshot?.exists ?? fs.existsSync(getConfigPath());
   const configAuditPath = path.join(resolveStateDir(process.env), "logs", "config-audit.jsonl");
   const mode = cfg.gateway?.mode;
   if (!opts.allowUnconfigured && mode !== "local") {
diff --git a/src/config/paths.ts b/src/config/paths.ts
index 18f8ab92663..fe0fe867124 100644
--- a/src/config/paths.ts
+++ b/src/config/paths.ts
@@ -182,8 +182,21 @@ export function resolveConfigPath(
   return path.join(stateDir, CONFIG_FILENAME);
 }
 
+/**
+ * @deprecated Use resolveConfigPathCandidate() instead. This constant is evaluated
+ * at module load time and does not respect OPENCLAW_HOME set after import.
+ * Kept for backwards compatibility but should be avoided in new code.
+ */
 export const CONFIG_PATH = resolveConfigPathCandidate();
 
+/**
+ * Runtime-evaluated config path that respects OPENCLAW_HOME.
+ * Use this instead of CONFIG_PATH when OPENCLAW_HOME may be set dynamically.
+ */
+export function getConfigPath(env: NodeJS.ProcessEnv = process.env): string {
+  return resolveConfigPathCandidate(env, envHomedir(env));
+}
+
 /**
  * Resolve default config path candidates across default locations.
  * Order: explicit config path → state-dir-derived paths → new default.
@@ -258,6 +271,22 @@ export function resolveGatewayPort(
   cfg?: OpenClawConfig,
   env: NodeJS.ProcessEnv = process.env,
 ): number {
+  // When OPENCLAW_HOME is set (isolated instance), prefer config over inherited env vars.
+  // This prevents a parent gateway's OPENCLAW_GATEWAY_PORT from bleeding through.
+  const isIsolatedInstance = Boolean(env.OPENCLAW_HOME?.trim());
+
+  // Config port takes precedence for isolated instances
+  const configPort = cfg?.gateway?.port;
+  if (
+    isIsolatedInstance &&
+    typeof configPort === "number" &&
+    Number.isFinite(configPort) &&
+    configPort > 0
+  ) {
+    return configPort;
+  }
+
+  // Check env vars (for non-isolated or when config doesn't specify port)
   const envRaw = env.OPENCLAW_GATEWAY_PORT?.trim() || env.CLAWDBOT_GATEWAY_PORT?.trim();
   if (envRaw) {
     const parsed = Number.parseInt(envRaw, 10);
@@ -265,11 +294,11 @@ export function resolveGatewayPort(
       return parsed;
     }
   }
-  const configPort = cfg?.gateway?.port;
-  if (typeof configPort === "number" && Number.isFinite(configPort)) {
-    if (configPort > 0) {
-      return configPort;
-    }
+
+  // Fall back to config for non-isolated instances
+  if (typeof configPort === "number" && Number.isFinite(configPort) && configPort > 0) {
+    return configPort;
   }
+
   return DEFAULT_GATEWAY_PORT;
 }